Possible types of Alien Lifeforms (Part 1: Mirror Life)

On Earth, life uses what is called right-handed DNA. Right-handed DNA uses left-handed amino acids, sometimes described as homochiral. The fact that all lifeforms on Earth use Right-handed DNA suggests that all life here is descendant from a common group of ancestors.

Why does the difference matter? If single cell members of mirror life (with left-handed DNA) are placed in a nutrient broth consisting of only left-handed amino acids, the lifeforms will not be able to thrive. The same is true of the reverse.

Mirror life is a type of lifeform that uses the same type of DNA structure, but where the DNA is left-handed. This type of life, in turn, used right-handed amino acids.

The possibly that life on other worlds may be mirror life is very exciting. If found, it would lend tremendous evidence that life is possible in other forms as well.

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Reference: "Are Aliens Among Us?" by Paul Davies, Scientific American December 2007

Related articles

• Video: What Would Trees Look Like On Other Planets?
• Predictions of Evolution of Alien Life
• Communicaion with Alien Civilizations
• Odds of Humaniods Evolving again
• Part 5: Blue Plants
• Part 4: Silicon Life
• Part 3: Arsenic Life
• Part 2: Exotic Amino Acids
• Part 1: Mirror Life

Something in the Air

I recently wrote an article about the platypus species being the most primitive of all mammals. Funny that only a couple months later there is now a news story about this vary same thing. The news story is originally from Livescience.com here. There is new interesting information about the fact that although the platypus has the X and Y chromosomes, these are not the sex chromosomes for the platypus. Instead, the platypus has about 10 other chromosomes for that purpose. Strange animal, this platypus

Evolution of Mammal Traits

Sometimes I'm fascinated at how mammals become mammals. Most mammals are so similar to one another in our number of traits that it amazes me to think that the diversity of mammals today came from a very small number of species in the past. One trait the most people don't even know about is our acute hearing. I imagine most people never think about how we mammals hear differently than other species. We have three bones in our inner ear, two of which are unique to us. (Most animals use parts of their jaw bones to hear.) Another unique adaption is the fact that we feed our young with milk from the mother. This is such as complex function, I can imagine why some people find it easier to accept we are just "made" this way. However, there is evidence that shows the path of evolution, and it isn't in the form of fossils.

The platypus is likely the most primitive mammal alive today. It lays eggs. It does feed it's young with a milk-like secretion, but not with nipples. Instead, it has a hairy patch its underside. The secretions not only serve to feed their young, but apparently, it also adds an additional layer of protection to the egg shell before the hatchlings emerge.

Then, the path to marsupials is given to us in the form of the second most primitive mammal, the echidna. This is a group of a few species that also lay eggs. However, when it lays its eggs, it places them into a pouch. This likely represents a primitive marsupial, before egg laying was replaced by embryo birth.

Marsupials in turn do have one advantage to placental mammals (that's us). There are less complications from having to protect the embryo from the mothers immune system since the young leave the womb at such an early stage.

Of course, the advantage of having a placenta during pregnancy has its own advantages, which can be seen by the fact that placental mammals are now the dominate form of mammals.

Even given our high level of development, one can see that mammals have not dominated the Earth for very long. For example, there are far fewer varieties of mammals than reptiles. Given the advancements of mammals, it will be interesting to see what future classes of species evolve on our world.

Fruitcake for Xmas

According to a recent Reuters report, a Christian biologist is suing Woods Hole Oceanographic Institution for firing him because he believes against evolution (claiming civil liberties violation). This Christian "biologist" is now working for Rev. Jerry Falwell's Liberty University. This strikes me as a bit convenient. This guy gets a job at a respected institute and then reveals he believes against scientific fact after he's hired, and is now working at a religious institution? Hmm, sounds like a set up to me. I wouldn't be surprized if he applied at all the major places hoping to catch a big fish to bring this issue up (knowing that Liberty University or something similar would be available for him to fall back on). He prolly was already conspiring with his religious buddies before he even went to college to get his degree in biology.
Sorry to disappoint, a person who believes against scientific fact does not get protection under the Constitution and modern Civil Liberties as a protected class when it comes to a job that needs acknowledgement of scientific fact in order to perform required tasks, nor is someone that conspires against reality. A person can be fired for what they choose to say Not to mention the fact that believing against scientific fact precluded him from being able to perform his job at a scientific institution!
In good conscience, I don't know how he could call himself a biologist. I would go so far as to note that his biologist degree doesn't have validity if he decries the basis upon which it was based. If he really does believe against scientific fact, he should return his degree to the institution which issued it to him and obtain a new degree in Religious Studies or something.

Superstitious metaphor

I am superstition only to the extent that I know thinking about something contributes to making it real to me. The new goal I set for myself is to focus on what I desire, and discontinue thoughts on that which I spurn. I feel this simple truth is nothing new, however. It was expressed by the ancients through metaphor, in the form of stories about gods. In that, I do not hold any beliefs regarding gods. When I do refer to god, it is simply the knowing use of such as a metaphor. Another metaphoric use of gods employed by the ancients was to plainly explain and understand what was then unknowable. As knowledge increases, that metaphor loses value.

However, this does not mean I deny the spiritual or supernatural experience. Too many people from every realm on Earth, in every known time frame, and walk of life have extraordinary experiences that go beyond simple physical world explanation. Too easy is it when someone who is void of such experiences attributes anecdotal recountings to the devil or imagination. I regard these dismissals as silly.

Even after experiencing something extraordinary, it is hard for some to understand the experience properly because they have been so indoctrinated with a system of beliefs. How much less so can someone who has not experienced a thing judge one who has?

The question is why have beliefs? Why not base everything on the self-quest for knowledge? I find that I seek out what others have learned, and augment that with my own experiences. For example, I know that terrestrial life develops over time through the processes of evolution and natural selection, but I do not hold a belief about these. I simply know that discernable and testable evidence makes knowledge about these processes more clear. I don’t try to fit in a god into my understanding of these processes. Nor do I try to use my limited knowledge of these processes to come up with unsupported conclusions that I then rigidly believe. In other words, I do not hold any beliefs about how life got started, even though I have knowledge about how it develops. I am aware of notions and ideas about the origin of life, but I treat these has just that. I do not need to have a belief regarding the origin of life in order to know that evolution is currently the best description of those processes.

My experience is that Christians and Atheists alike are too easy to judge something based on beliefs they hold, rather than on the human experience itself. To a supernatural event, the Christian will say, “It was God’s will” or “The devil did that”. To that same event, the Atheist will say, “It was your imagination” or “You misinterpreted the event; there must be a logical explanation.” To this I say that’s pretty arrogant to assume that they know the answer outright. In particular, this is the one area with Atheist are hypocrites because the general idea behind atheism is the lack of beliefs without evidence. If they have no evidence one way or another, they normally don’t jump to conclusions, except when something supernatural or spiritual is being questioned. Of course, Christians just make stuff up in their heads as they go along, in order to fit everything into their picture of this world created from their overly literal, under-educated understanding of ancient texts.

It’s expected to develop notions about something, and to test those as hypothesis. Most of us are in the wrong profession and/or will simply not live long enough to have the time to challenge every hypothesis or theory for ourselves. So, some bit of trust has to be placed in the works of others. Just as long as everything is understood as not absolute, it’s ok to accept reasonable margins of error in one’s knowledge.

I am not an atheist. I am not religious either. To me, both are contrary to my experiences and gathered knowledge. Both have had value in the process of developing my current knowledge base. They are not useless. They are both stepping stones to gaining experience and knowledge in one’s life. They both have their place, though neither can be used as reason to end the search for new knowledge and experiences.

Focusing one’s thoughts on a god can make that god real to that person. But each of us has the power to create our own metaphoric god. Judging someone’s metaphor is ultimately a judgment of our own. In this, I am also a little superstitious. Do not judge, lest ye be judged. Of course, I’m not perfect. I judge all the time. It’s the effort that counts; at least in my metaphor.

Driving with fish

A major realization hit me about a year ago. People drive on the freeway in a fashion that is similar to schooling fish in the ocean. People tend to try to drive in packs. I think these packs naturally form as a result of our schooling/herding instinct that still lies deep in ourselves. Even in driver's ed, I learned that people will tend to try to drive in packs. I've heard these packs referred to by a variety of names, but ultimately, I think the herding instinct is a holdover when we where fish living in schools, hundreds of millions of years ago. This instinct was almost completely dorminate until billions of us got behind the wheel of a car during the 20th Century.
For example, when you pull up on someone's side in the next lane at about 5 mph faster, there is a pretty high chance of that person slightly speeding up to match your speed. And the same is true in the opposite. If you are ahead of someone that is slowing pulling up on you in the next lane, there is a high chance of that person slowing down to match your speed, usually in your blind spot. Of course, this usually occurs when you need to get into the land into that space they occupy.
I've learned to work around this and use my knowledge to my advantage. I know that powering ahead instead of just cruising ahead will actually cause most others to ignore me instead of trying to join me.

Star birth linked to waves of life on Earth

I found this interesting article (backup link) that proposes a link between new star generation in our Milky Way galaxy with the waves of bacteria life in Earth's past. Quick quote:

"Dr Svensmark noticed that the biggest fluctuations in [bacterial lifeform] productivity coincided with high star formation rates and cool periods in Earth's climate. Conversely, during a billion years when star formation was slow, cosmic rays were less intense and Earth's climate was warmer, the biosphere was almost unchanging in its productivity."

This idea is interesting because it demonstrates just how linked we are, not just to the Earth, but the cosmos as a whole.

Evolution meets reality

The Theory of Evolution doesn’t exist as a counter to the bible or belief in gods.  It is founded upon geology, paleontology, archeology, biology, chemistry, etc.  It exists to provide common-sense, factual explanations of the evidence, as a result of using the principles upon which it stands, based on scientific discoveries made throughout the 17th to 21st Centuries.

In particular, discoveries in geology forced scientist to recognize that Earth is far older than stated by common interpretations of the bible.  These discoveries are summed up in a series of geological principles. Andrew MacRae of TalkOrigins states, “Most of these principles were formally proposed by Nicolaus Steno (Niels Steensen, Danish), in 1669, although some have an even older heritage that extends as far back as the authors of the Bible.  An early summary of them is found in Charles Lyell's Principles of Geology, published in 1830-32, and does not differ greatly from a modern formulation.”

The principles are as follows:

1. Principle of Superposition - in a vertical sequence of sedimentary or volcanic rocks, a higher rock unit is younger than a lower one. "Down" is older, "up" is younger.  This is more commonly called "Law of Superposition" nowadays.
2. Principle of Original Horizontality - rock layers were originally deposited close to horizontal.
3. Principle of Lateral Continuity - A rock unit continues laterally unless there is a structure or change to prevent its extension.
4. Principle of Cross-cutting Relationships - a structure that cuts another is younger than the structure that is cut.
5. Law of Included Fragments - a structure that is included in another is older than the including structure.
6. The principle of "uniformitarianism" - processes operating in the past were constrained by the same "laws of physics" as operate today.  This particular principle is not longer viewed as a necessary factor of modern science, but was important for those who lived in a time when most people considered ancient myths as fact.

In science, a principle (or law) is a description of a phenomenon in a particular situation without considering the cause based on evidence.  Laws are commonly retested just as everything is in science.  If a scientist comes across evidence that seems to contradict a known principle or law, that scientist understands that the principle needs retesting to determine how their new data fits into the overall collection of observations.  For example, the principle of original horizontality basically says that sedimentary layers of rock in the ground must be laid horizontality.  However, many rock formations are made up of sedimentary layers that are nearly vertical.  Is the original horizontality wrong?  No.  The layers where originally laid horizontally. Shifts in the Earth’s crust caused the layers to be moved into a nearly vertical position long after they were laid.  This particular observation was a factor in allowing scientists to eventually discover Plate Tectonics.

What does this have to do with the Theory of Evolution?  Even before radioactive dating, these geological principles forced scientists to realize that the Earth must be at least millions of years old.  Further, fossils of life forms are present in various layers of rock.  The fossil record shows a progressive change in life forms on Earth over time.  There is no period in which every species (particularly plants and animal) exist at the same time.  This led curious minds to ask, what is the process for bringing about new species over time?  Creationism said that all creatures were created in the beginning, but the fossil record shows that species come into existence and died out over different and vast periods of time.

Enter Darwin’s exploration.  He studied modern examples of plants and animals, and understood the fossil record.  His research and publication led to the discoveries of evolution and natural selection.  Why does life change over time?  It evolves.  What is the main driving force of evolution?  It is natural selection.

Darwin didn’t actually create the Theory of Evolution.  A theory cannot be made by one person.  A theory is the working explanation for repeatable observations and predictions in nature that are supported by scientific evidence and verified multiple times by various groups of researchers via peer review processes.  To briefly paraphrase Karl Popper, scientific theories must have testability (ability to test the theory), falsifiability (test if the theory is false), or refutability (test if the theory is refutable).

Evidence collected and verified by this process throughout the 20th Century did nothing but continue to reinforce the Theory of Evolution.  The fossil record became more complete and understanding of genetics improved.  Richard Lenski states, “Using DNA sequences, biologists quantify the genetic similarities and differences among species, in order to determine which species are more closely related to one another and which are more distantly related.  In doing so, biologists use essentially the same evidence and logic used to determine paternity in lawsuits.  The pattern of genetic relatedness between all species indicates a branching tree that implies divergence from a common ancestor.”

In the 21st Century, new discoveries in biology are not only further proving evolution; they are actually using knowledge of evolution to make new discoveries, particularly in areas of battling diseases, as mentioned in the article “Antibiotics in Action” at Pharmaceutical Achievers.  In other words, the Theory of Evolution is practical science benefiting humankind directly.  This puts the Theory of Evolution in the same league as Universal Law of Gravitation, Music Theory, theories within Mathematics, and General Relativity.

So, why is this important?  The key difference between notions based on Creationism such as Intelligent Design and actual theories such as Evolution is in their value to science.  Intelligent Design is the end of knowledge. It cannot be tested. It leads to no further discoveries.  It does not improve our understanding of the world around us.  On the other hand, Theory of Evolution is the beginning of knowledge. It is a model of science being used in practical ways. It also leads to more discoveries with endless possibilities.  The value of Theory of Evolution is that is expands our knowledge.  Just as geology opened the door to discovering Evolution, Theory of Evolution is opening the doors to many other sciences involving biology, biotechnology, infectious diseases, genetics, environmentalism, farming, etc.  It leads to a better understanding of the world around us as a logical result of the many observations we make of that world.

References:
Andrew MacRae
Karl Popper
Richard Lenski
Antibiotics in Action

Unusual attention on an old post

Sometime last year, I posted a light-hearted commentary on the idea of viewing human history in human-centric terms titled Something about Evolution Just Occured to Me. What's odd is that this posting has just recently provoked a healthy array of comment responses.

Sometimes too cleaver

Some websites can be a bit too cleaver. I was going to post a link to an article that appeared in the Feb 1-8, 2006 Seattle Weekly which detailed the fall from grace experienced by the Discovery Institute in their efforts to combat reality with the highly fictional "Intelligent Design" notion. Well, Seattle Weekly does have their back issues on their website, but in the form of an Active X controlled pseudo-PDF format. Not so easy to link to, though it does store the exact pages as they appeared in the periodical when printed. I still recommend reading the article entitled Discovery's Creation. Goto Seattle Weekly and click on the Print Edition link under the Home tab. The browse for the Feb 1-8 issue under the back issue folder in the left menu, then goto page 19. It's not as hard as it sounds, but still is way too many steps when all would be needed is a direct link.
Anyways, the article does a good job of laying waste those nut-jobs at the Discovery Institute in light of recent Federal Court decisions reaffirming the lunacy of "Intelligent Design". It's a good read, and worth the time it takes to click through all those steps.